The next major promotional event for the Bumblebee Movie will be SDCC at the end of this month (July 19th to 22nd), with Paramount hosting a presentation panel, and I would expect that Hasbro will be officially revealing the Movie toys as well.
The Paramount movie panel is expected to include the Director Travis Knight, along with three of the cast - Hailee Steinfeld, John Cena, and Jorge Lendeborg Jr.
The panel will be on Friday July 20th, from 5 to 6pm... and should feature new footage (as upcoming movies do at SDCC).

US theatres are starting to receive their promo materials for the Bumblebee Movie, so we might see it in theatres here soon too.
No images yet of the contents of the promo box, but should be in the next couple days.